first of all, have all your band members do their part by learning (be it self-taught or lessons).
once you're all more or less comfortable with your equipment and have the fundamentals right, you can start playing songs. pick a song, and have your band members learn their parts before jamming together. this is very important. make sure they learn their parts well before jamming or else it'd be a complete waste of time.
once you guys have learned the song by heart, and know the song really well, get together and jam. it is very important that all the members know the song really well or it could lead to a lot of arguing and disharmony.
practice the song long enough that every member knows exactly when to play what and can synchronize. it would sound terrible if there was a pause, and your guitarist continues playing while all the rest stop. (get the idea?)
remember to start with something simple. you can look into playing songs by blink 182 and green day.
as you continue jamming and picking up the instruments on your part, the difficulty of the songs played will increase over time. this is when your band should try playing songs of different genres to expose your band to different types of music. this eventually helps when you're writing originals.
over time, you and your band will (hopefully) find a genre that you ALL like to play. it is a MUST for bands to have a same common interest and direction in order for the band to progress further.
once the common interest/direction is set, and your skills have greatly improved, you can start writing originals. this is where exposing yourself to different genres help. with the exposure that you have, you can add in little bits and pieces gathered across the genres to give your music a special twist.
and the list carries on... you go for gigs, recognition, make it big, die a rockstar blah blah...
all this will take a long time. improving and growing as a band doesn't happen overnight. be sure never to leave your band on impulse. you should only leave your band when there are MAJOR differences that AFFECT YOUR PLAYING that CANNOT BE RESOLVED.
oh do note that throughout this process, you should spend time to gel with your band. your band would progress a lot more if you were more than just a band. be friends with each other. a band isn't just about the music. it's about the company as well.
hope that helps